How can an object change its class?

I have two classes that for example purposes I'll call Enteroand Flotante. I need a method for an object to change classes on its own, without the intervention of external code.

The desired result is illustrated by the following pseudo-code:

class Entero:
    def __init__(self, valor: int):
        self.valor = valor

    def convertir_a_flotante(self):
        self.valor = float(self.valor)
        # Aqui cambiar la clase del objeto a Flotante.

class Flotante:
    def __init__(self, valor: float):
        self.valor = valor

    def convertir_a_entero(self):
        self.valor = int(self.valor)
        # Aqui cambiar la clase del objeto a Entero.

a = Entero(1)
print(f"Type(a) = {type(a)}") => Type(a) = <class '__main__.Entero'>
a.convertir_a_flotante()
print(f"Type(a) = {type(a)}") => Type(a) = <class '__main__.Flotante'>

The idea is not to generate a new object, but to preserve the existing one, so that previous references to the object are still valid.

Edition

With CalumRakk's answer and Abulafia's comments, I made a second version to check that the mutated object is really of the new class, implementing the common method__str__

class Entero:
    def __init__(self, valor: int):
        self.valor = valor

    def convertir_a_flotante(self):
        self.valor = float(self.valor)
        self.__class__=Flotante

    def __str__(self):
        return f"Entero {self.valor}"

class Flotante:
    def __init__(self, valor: float):
        self.valor = valor

    def convertir_a_entero(self):
        self.valor = int(self.valor)
        self.__class__=Entero

    def __str__(self):
        return f"Flotante {self.valor}"

a = Entero(1)
print(a, type(a))
a.convertir_a_flotante()
print(a, type(a))

which produces:

Entero 1 <class '__main__.Entero'>
Flotante 1.0 <class '__main__.Flotante'>

Process finished with exit code 0